1. Field of the Invention
The present invention relates to a consumable product unit, a consumable product replacement sensing system and a method thereof, and more particularly, to a consumable product unit, a consumable product replacement sensing system and a method thereof, for recognizing whether or not a new consumable product unit is mounted in a system, as a replacement, and determining whether or not the new consumable product unit is one to use in the system, both of which by using a single circuit.
2. Description of the Related Art
Generally, a photocopier, a printer, a facsimile machine, and a multi-function machine having multi-functions of the photocopier, the printer, and the facsimile machine are types of electrophotograph printing apparatuses. Such a printing apparatus forms an image such that the printing apparatus provides a solid type developer, such as a toner, to a photosensitive medium where an electrostatic latent image forms or the printing apparatus jets a liquid type developer onto the photosensitive medium, and prints an image corresponding to the electrostatic latent image on a paper passing through rollers rotating and in contact with the photosensitive medium.
Consumable products such as a developer or a photosensitive belt of the printing apparatus are consumed or wear out as a result of a continuous use thereof. Accordingly, the consumable products, such as the developer and photosensitive belt are required to be replaced with new ones at proper times. For a replacement of the consumable products, a conventional printing apparatus comprises separate determination circuits to determine whether a newly replaced consumable product is a new consumable product or a used consumable product and to determine whether or not the consumable product is usable in the printing apparatus.
Therefore, the conventional printing apparatus requires an intermediate path circuit having a plurality of ports to connect with the respective determination circuits to an engine control unit. Since the intermediate path circuit is fabricated by an application-specific integrated circuit (ASIC) to have the plurality of ports, a problem of increased fabrication costs exists.